1. Field of the Invention
The present invention relates to a method for the production of corrugated paper, and more particularly to a method which corrugates the paper with longitudinal ridges and grooves, rather than transverse corrugations.
2. Description of the Prior Art
Various methods and equipment have been proposed in the prior art for the production of corrugated paper. In U.S. Pat. No. 2,257,428, issued to Ruegenberg on Sept. 30, 1941, there is described a method and apparatus for making folds for crinkles in paper. The Ruegenberg method is described as useful with an all-around extensible and elastic paper or production of crepe paper or the like. This patent describes the use of a series of straight rollers positioned in parallel to make increasing depth to the folds.
A similar process and machine are described in U.S. Pat. No. 2,901,951, issued to Hochfeld on Sept. 1, 1959. The Hochfeld patent also describes the use of a series of parallel, straight line rollers which give increasing depth to the paper folds. In both the Ruegenberg and Hochfeld patents, it is significant that the use of the straight line rollers requires that the paper take different length paths depending on its location relative the rollers. This is one difficulty in the prior art which is overcome by the present invention.
In U.S. Pat. Nos. 2,276,737, issued to Plewes et al. on Mar. 17, 1942 and 1,975,548, issued to Ives on Oct. 2, 1934, there are described methods and devices for crimping and fluting paper at an angle to the direction of travel of the paper. Typical devices for crimping paper transverse of its direction of travel are disclosed in U.S. Pat. Nos. 1,896,037, issued to Boeye on Jan. 31, 1933 and 2,974,716, issued to Fourness on Mar. 14, 1961.